Thin film and preparation method thereof, photoelectric device and preparation method thereof, and display device

Abstract

The embodiment of the invention provides a thin film and a preparation method thereof, a photoelectric device and a preparation method thereof, and a display device. The film comprises nanocellulose and inorganic nanoparticles, the nanocellulose has a porous skeleton, the inorganic nanoparticles are located in pores of the porous skeleton, and by doping the tough nanocellulose into the inorganic nanoparticles, the inorganic nanoparticles can be embedded into the skeleton of the nanocellulose, so that the toughness of the film is improved; the framework of the nanocellulose can limit the movement of the inorganic nanoparticles, so that the displacement of the inorganic nanoparticles in the bending process of the film can be reduced, the condition of cracks or fractures of the film in the bending process can be slowed down or eliminated, and the bending resistance of the film is improved.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic devices, and particularly to a thin film, a preparation method thereof, an optoelectronic device, a preparation method thereof, and a display device. Background Art

[0002] Electroluminescent devices include OLED (Organic Light-Emitting Diode) and QLED (Quantum Dot Light Emitting Diodes). QLED has advantages such as high color saturation, wet processability, and high stability, which has attracted more and more attention in the research of QLED. OLED has wide applications in the fields of display, lighting, and smart wear due to its good self-luminous characteristics, high contrast, fast response, and flexible display.

[0003] The functional layer in an electroluminescent device can be a thin film composed of multiple inorganic nanoparticles (such as quantum dot particles). However, such a thin film has poor bending resistance. When bent under external force, cracks or even fractures often occur in the thin film due to the displacement of inorganic nanoparticles in the thin film, which will cause changes in the carrier transport of the electroluminescent device and thus lead to a decline in the performance of the electroluminescent device. Summary of the Invention

[0004] Based on this, embodiments of the present application provide a thin film, a preparation method thereof, an optoelectronic device, a preparation method thereof, and a display device.

[0005] In a first aspect, embodiments of the present application provide a thin film, including nanocellulose and inorganic nanoparticles. The nanocellulose has a porous framework, and the inorganic nanoparticles are located in the pores of the porous framework.

[0006] In some embodiments, the mass ratio of the nanocellulose to the inorganic nanoparticles is (0.01 - 0.05):1; and / or

[0007] The nanocellulose includes at least one of cellulose nanocrystals, cellulose nanofibers, and bacterial nanocellulose.

[0008] In some embodiments, the thin film further includes a crosslinking agent, and the crosslinking agent includes at least one of silane and anhydride;

[0009] The silane is connected to the nanocellulose; and / or

[0010] The anhydride is connected to the nanocellulose; and / or

[0011] The mass ratio of the cross-linking agent to the nanocellulose is (0.5-10):100.

[0012] In some embodiments, the silane is connected to the nanocellulose via at least one silicon-oxygen bond; and / or

[0013] The acid anhydride is connected to the nanocellulose via at least one ester bond.

[0014] In some embodiments, the silane includes at least one of 3-aminopropyltriethoxysilane, methyltrioxysilane, styrenedimethoxysilane, and aminopropyltrimethoxysilane; and / or

[0015] The acid anhydride comprises at least one of maleic anhydride, succinic anhydride and phthalic anhydride; and / or

[0016] The cross-linking agent is silane, and the mass ratio of the cross-linking agent to the nanocellulose is (0.5-5):100; or

[0017] The cross-linking agent is an acid anhydride, and the mass ratio of the cross-linking agent to the nanocellulose is (1-10):100; or

[0018] The crosslinking agent comprises a mixture of silane and anhydride, and the mass ratio of silane to anhydride is (1-100):(1-100).

[0019] In some embodiments, the material of the inorganic nanoparticles includes at least one of an organic light-emitting material and a quantum dot light-emitting material, and the organic light-emitting material includes 4,4'-bis(N-carbazole)-1,1'-biphenyl:tri[2-(p-tolyl)pyridine iridium(III), 4,4',4"-tri(carbazole-9-yl)triphenylamine:tri[2-(p-tolyl)pyridine iridium, diaryl anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, 1,4,7,10-tetra-tert-butyl perylene, rubrene derivatives, thermally activated delayed fluorescence materials, excimer complexes The quantum dot luminescent material comprises one or more of a single structure quantum dot and a core-shell structure quantum dot, and the material of the single structure quantum dot, the core material of the core-shell structure quantum dot and the shell material of the core-shell structure quantum dot each independently comprise at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound, and the shell layer of the core-shell structure quantum dot comprises one or more layers;The II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, H At least one of CdZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, wherein the IV-VI group compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, at least one of SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, the III-V group compound is selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, and the I-III-VI group compound is selected from at least one of CuInS; 2 、CuInSe 2 AgInS 2 At least one of .

[0020] In a second aspect, an embodiment of the present application provides a method for preparing a thin film, comprising:

[0021] Providing an inorganic nanomaterial solution, wherein the inorganic nanomaterial solution comprises nanocellulose, inorganic nanoparticles and a solvent;

[0022] The inorganic nano material solution is deposited to obtain a film, which includes nano cellulose and inorganic nano particles. The nano cellulose forms a porous skeleton, and the inorganic nano particles are located in the pores of the porous skeleton.

[0023] In some embodiments, in the inorganic nanomaterial solution, the concentration of the inorganic nanoparticles is 10 mg / ml to 50 mg / ml, and the concentration of the nanocellulose is 0.1 mg / ml to 2.5 mg / ml; and / or

[0024] The mass ratio of the nanocellulose to the inorganic nanoparticles is (0.01 - 0.05):1.

[0025] In some embodiments, the inorganic nanomaterial solution further includes a crosslinking agent, the crosslinking agent includes at least one of silane and anhydride, and the mass ratio of the crosslinking agent to the nanocellulose is (0.5 - 10):100;

[0026] The concentration of the crosslinking agent in the inorganic nanomaterial solution is 0.0005 mg / ml to 0.25 mg / ml.

[0027] In some embodiments, when the crosslinking agent is silane, the mass ratio of the crosslinking agent to the nanocellulose is (0.5 - 5):100, and the concentration of the crosslinking agent in the inorganic nanomaterial solution is 0.0005 mg / ml to 0.125 mg / ml;

[0028] When the crosslinking agent is anhydride, the mass ratio of the crosslinking agent to the nanocellulose is (1 - 10):100, and the concentration of the crosslinking agent in the inorganic nanomaterial solution is 0.001 mg / ml to 0.25 mg / ml.

[0029] In some embodiments, depositing the inorganic nanomaterial solution to obtain a thin film includes:

[0030] Depositing the inorganic nanomaterial solution to obtain a film layer to be crosslinked;

[0031] Heat-treating the film layer to be crosslinked in an environment with a temperature of 80°C to 100°C and a humidity of 80% to 100% for 10 minutes to 60 minutes, and the crosslinking agent and the nanocellulose undergo a crosslinking reaction to obtain a thin film.

[0032] In a third aspect, an embodiment of the present application provides an optoelectronic device, including:

[0033] A first electrode;

[0034] A second electrode, disposed opposite to the first electrode;

[0035] A thin film, disposed between the first electrode and the second electrode, and the thin film is the thin film as described above or the thin film prepared by the preparation method of the thin film as described above.

[0036] In some embodiments, when the first electrode is an anode and the second electrode is a cathode, the photoelectric device further comprises a hole injection layer and a hole transport layer between the film and the first electrode and an electron transport layer between the film and the second electrode, wherein the hole injection layer is disposed close to the first electrode and the hole transport layer is disposed close to the film; or

[0037] When the first electrode is a cathode and the second electrode is an anode, the photoelectric device further comprises an electron transport layer between the film and the first electrode, and a hole injection layer and a hole transport layer between the film and the second electrode, wherein the hole injection layer is arranged close to the second electrode, and the hole transport layer is arranged close to the film.

[0038] In some embodiments, the material of the hole transport layer includes 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl))-biphenyl aniline), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N ,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] , 1,3-di(carbazole-9-yl)benzene, polyaniline, polypyrrole, poly(p-)phenylene vinylene, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, polyspirofluorene and its derivatives, polythiophene and its derivatives; and / or

[0039] The material of the hole injection layer includes at least one of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and its derivatives, copper phthalocyanine, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, poly(dioxyethylthiophene), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, transition metal oxides and transition metal sulfur compounds; and / or

[0040] The material of the electron transport layer includes at least one of metal oxide, doped metal oxide, II-VI semiconductor material, III-V semiconductor material and I-III-VI semiconductor material, and the metal oxide is selected from ZnO, BaO, TiO 2 SnO 2 At least one of the following; the metal oxide in the doped metal oxide is selected from ZnO, TiO 2 SnO 2 At least one of the doping elements is selected from at least one of Al, Mg, Li, In, and Ga; the II-VI semiconductor material is selected from at least one of ZnS, ZnSe, and CdS; the III-V semiconductor material is selected from at least one of InP and GaP; the I-III-VI semiconductor material is selected from at least one of CuInS and CuGaS; and / or

[0041] The first electrode and the second electrode are independently selected from a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode. The material of the doped metal oxide particle electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide. The composite electrode includes AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO 2 / Ag / TiO 2 、TiO 2 / Al / TiO 2 , ZnS / Ag / ZnS or ZnS / Al / ZnS, the material of the metal single substance electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba.

[0042] In a fourth aspect, an embodiment of the present application provides a method for preparing an optoelectronic device, comprising:

[0043] Providing a photoelectric device preform, wherein the photoelectric device preform comprises a first electrode;

[0044] Prepare a thin film on the first electrode using the thin film preparation method described above;

[0045] A second electrode is formed on the film to obtain a photoelectric device.

[0046] In some embodiments, when the first electrode is an anode and the second electrode is a cathode, the thin film preparation method described above is used to prepare a thin film on the first electrode, comprising: forming a hole injection layer on the first electrode, forming a hole transport layer on the side of the hole injection layer away from the first electrode, and preparing a thin film on the hole transport layer using the thin film preparation method described above;

[0047] The forming of the second electrode on the thin film comprises: forming an electron transport layer on the thin film, and forming the second electrode on a side of the electron transport layer away from the thin film.

[0048] In some embodiments, when the first electrode is a cathode and the second electrode is an anode, the preparing a thin film on the first electrode using the thin film preparation method described above includes: forming an electron transport layer on the first electrode, and forming a thin film on a side of the electron transport layer away from the first electrode using the thin film preparation method described above;

[0049] The forming of the second electrode on the thin film comprises: forming a hole transport layer on the thin film, forming a hole injection layer on the side of the hole transport layer away from the thin film, and forming the second electrode on the side of the hole injection layer away from the hole transport layer.

[0050] In a fifth aspect, an embodiment of the present application provides a display device, comprising the optoelectronic device as described above or an optoelectronic device manufactured by the method for manufacturing the optoelectronic device as described above.

[0051] The film provided in the embodiment of the present application, by adding tough nanocellulose to inorganic nanoparticles, can embed the inorganic nanoparticles into the skeleton of nanocellulose to limit the movement of the inorganic nanoparticles, thereby reducing the displacement of the inorganic nanoparticles during the bending process of the film, and further can slow down or eliminate the cracks or breakage of the film during the bending process, thereby improving the bending resistance of the film; when the film of the embodiment of the present application is applied to flexible optoelectronic devices, since the film has good bending resistance, it can extend the service life of the flexible optoelectronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments.

[0053] Figure 1 A flow chart of a method for preparing a thin film provided in an embodiment of the present application.

[0054] Figure 2 A schematic diagram of the first structure of the optoelectronic device provided in an embodiment of the present application.

[0055] Figure 3 A second structural schematic diagram of the optoelectronic device provided in an embodiment of the present application.

[0056] Figure 4 A flow chart of a method for preparing a photoelectric device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0058] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0059] In the present application, "at least one" means one or more, and "plurality" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c" can all mean: a, b, c, a+b, a+c, b+c, or a+b+c, where a, b, c can be single or multiple, respectively.

[0060] In the present application, when another layer is formed "on" a certain layer, the so-called "on" is a broad concept, which may indicate that the formed another layer is adjacent to the certain layer, or may indicate that there are other spacing structural layers between the another layer and the certain layer. For example, when a second electrode is formed "on" the first carrier functional layer, the so-called "on" may indicate that the formed second electrode is adjacent to the first carrier functional layer, or may indicate that there are other spacing structural layers between the second electrode and the first carrier functional layer, such as a light-emitting layer.

[0061] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0062] An embodiment of the present application provides a film, comprising nanocellulose and inorganic nanoparticles, wherein the nanocellulose has a porous skeleton, and the inorganic nanoparticles are located in the pores of the porous skeleton.

[0063] Exemplarily, the mass ratio of the nanocellulose to the inorganic nanoparticles is (0.01-0.05):1, such as 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, etc.

[0064] Exemplarily, the material of the inorganic nanoparticles may include at least one of an organic light-emitting material and a quantum dot light-emitting material.

[0065] For example, the organic light-emitting material may include, but is not limited to, 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine iridium(III)] (CBP:Ir(mppy) 3 ), 4,4',4"-tri(carbazole-9-yl)triphenylamine:tri[2-(p-tolyl)pyridineiridium (TCTX:Ir(mmpy)), diarylanthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, 1,4,7,10-tetra-tert-butyldinaphthylene (TBPe), rubrene derivatives (TBRb), thermally activated delayed fluorescence (TADF) materials, luminescent materials with hybrid localized-charge transfer (HLCT) excited state characteristics, exciplex luminescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives. One or more of them.

[0066] Exemplarily, the quantum dot luminescent material includes at least one of a single structure quantum dot and a core-shell structure quantum dot. Specifically, the material of the single structure quantum dot, the core material of the core-shell structure quantum dot and the shell material of the core-shell structure quantum dot can each independently include at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound. The shell layer of the core-shell structure quantum dot includes one or more layers. The II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, Hg Te, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZn At least one of S, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, group IV-VI The compound is selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, and the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, and GaPA At least one of GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb, and the I-III-VI group compound is selected from CuInS 2 、CuInSe 2 AgInS 2 At least one of .

[0067] In some embodiments, the inorganic nanoparticles are quantum dot particles.

[0068] The inventors of the present application have found in their research that when the mass ratio of nanocellulose to inorganic nanoparticles is (0.01-0.05):1, not only can the toughness of the film be enhanced, but also the conductive properties of the film will not be affected, so that the optoelectronic device has better electrical properties and a longer service life. It should be noted that when the mass ratio of the nanocellulose to the inorganic nanoparticles is greater than or equal to 0.01:1, when the film is bent or folded, the nanocellulose can well maintain the stability of the position of the quantum dot particles, thereby slowing down or eliminating the cracks or fractures of the film during the bending process, thereby improving the stability and service life of the optoelectronic device; when the mass ratio of the nanocellulose to the inorganic nanoparticles is less than or equal to 0.05:1, due to the low content of nanocellulose, the nanocellulose has less effect on the conductive properties of the film, and thus has less effect on the luminous efficiency of the optoelectronic device.

[0069] Exemplarily, the nanocellulose includes at least one of cellulose nanocrystals, cellulose nanofibers and bacterial nanocellulose.

[0070] Exemplarily, the film also includes a crosslinking agent, which includes at least one of silane and anhydride, and the mass ratio of the crosslinking agent to the nanocellulose is (0.5-10):100, for example, 0.5:100, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, etc.

[0071] It should be noted that due to the poor thermal stability of nanocellulose, nanocellulose may be destroyed in a high-temperature use environment or storage environment. Therefore, the embodiment of the present application adds a cross-linking agent to the film to allow different nanocellulose molecules or different segments in the same nanocellulose molecule to cross-link, thereby improving the thermal stability of the nanocellulose and further improving the thermal stability of the film.

[0072] Exemplarily, when the cross-linking agent is silane, the silane is connected to the nanocellulose. Exemplarily, the silane is connected to the nanocellulose via at least one silicon-oxygen bond.

[0073] It should be noted that silane can react with the hydroxyl groups of nanocellulose to generate siloxane. Since the same silane molecule can react with different nanocellulose molecules or with different segments in the same nanocellulose molecule, the nanocellulose can be cross-linked.

[0074] Exemplarily, when the cross-linking agent is a silane, the mass ratio of the cross-linking agent to the nanocellulose is (0.5-5):100, for example, 0.5:100, 1:100, 2:100, 3:100, 4:100, 5:100, etc., and the silane includes at least one of 3-aminopropyltriethoxysilane, methyltrisilane, styrenedimethoxysilane and aminopropyltrimethoxysilane.

[0075] Exemplarily, when the cross-linking agent is an acid anhydride, the acid anhydride is connected to the nanocellulose, and exemplary, the acid anhydride is connected to the nanocellulose via at least one ester bond.

[0076] It should be noted that when the cross-linking agent is an acid anhydride, the acid anhydride can undergo a ring-opening reaction with the hydroxyl groups of nanocellulose to generate esters. Since the same acid anhydride molecule can react with different nanocellulose molecules or with different segments in the same nanocellulose molecule, the effect of cross-linking the nanocellulose can be achieved.

[0077] Exemplarily, when the cross-linking agent is an acid anhydride, the mass ratio of the cross-linking agent to the nanocellulose is (1-10):100, for example, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, etc., and the acid anhydride includes at least one of maleic anhydride, succinic anhydride and phthalic anhydride.

[0078] Exemplarily, the crosslinking agent includes a mixture of silane and anhydride, and the mass ratio of silane to anhydride is (1-100):(1-100), for example, 1:1, 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 100:1, 90:1, 80:1, 70:1, 60:1, 50:1, 40:1, 30:1, 20:1, 10:1, etc. At this time, the mass ratio of the crosslinking agent to the nanocellulose is (0.5-10):100, for example, 0.5:100, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, etc.

[0079] Exemplarily, the thickness of the film is 10 nm-50 nm, for example, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, 45 nm, 48 nm, 50 nm, etc.

[0080] The film provided in the embodiment of the present application can embed the inorganic nanoparticles into the skeleton of nanocellulose by adding tough nanocellulose into the inorganic nanoparticles. Since the skeleton of nanocellulose can limit the movement of inorganic nanoparticles, the displacement of inorganic nanoparticles during the bending process of the film can be reduced, and then the cracks or breakages of the film during the bending process can be slowed down or eliminated, thereby improving the bending resistance of the film; by limiting the mass ratio of nanocellulose to inorganic nanoparticles to (0.01-0.05):1, the toughness of the film can be enhanced without affecting the conductive properties of the film, so that the optoelectronic device can have both good electrical properties and a long service life; when the film of the embodiment of the present application is applied to a flexible optoelectronic device, the film has good bending resistance, thereby extending the service life of the flexible optoelectronic device.

[0081] See also Figure 1 The present application provides a method for preparing a thin film, which can be used to prepare the thin film in any of the above embodiments. The method comprises:

[0082] S110, providing an inorganic nanomaterial solution, wherein the inorganic nanomaterial solution includes nanocellulose, inorganic nanoparticles and a solvent.

[0083] Exemplarily, the mass ratio of nanocellulose to the inorganic nanoparticles is (0.01-0.05):1.

[0084] Illustratively, the solvent includes at least one of octane, n-hexane, heptane, toluene, chloroform, and dichloromethane.

[0085] Exemplarily, in the inorganic nanomaterial solution, the concentration of the inorganic nanoparticles is 10 mg / ml to 50 mg / ml (for example, 10 mg / ml, 20 mg / ml, 30 mg / ml, 40 mg / ml, 50 mg / ml, etc.), and the concentration of the nanocellulose is 0.1 mg / ml to 2.5 mg / ml (for example, 0.1 mg / ml, 0.5 mg / ml, 0.8 mg / ml, 1.0 mg / ml, 1.2 mg / ml, 1.5 mg / ml, 1.8 mg / ml, 2.0 mg / ml, 2.2 mg / ml, 2.5 mg / ml, etc.).

[0086] Exemplarily, the inorganic nanomaterial solution also includes a crosslinking agent, which includes at least one of silane and anhydride, and the mass ratio of the crosslinking agent to the nanocellulose is (0.5-10):100, for example, 0.5:100, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, etc.

[0087] Illustratively, the concentration of the cross-linking agent in the inorganic nanomaterial solution is 0.0005 mg / ml to 0.25 mg / ml, for example, 0.0005 mg / ml, 0.001 mg / ml, 0.005 mg / ml, 0.01 mg / ml, 0.05 mg / ml, 0.1 mg / ml, 0.125 mg / ml, 0.15 mg / ml, 0.2 mg / ml, 0.25 mg / ml, etc.

[0088] Exemplarily, when the cross-linking agent is silane, the mass ratio of the cross-linking agent to the nanocellulose is (0.5-5):100, and the concentration of the cross-linking agent in the inorganic nanomaterial solution is 0.0005 mg / ml-0.125 mg / ml, for example, 0.0005 mg / ml, 0.001 mg / ml, 0.005 mg / ml, 0.01 mg / ml, 0.05 mg / ml, 0.1 mg / ml, 0.125 mg / ml, etc.

[0089] When the cross-linking agent is an acid anhydride, the mass ratio of the cross-linking agent to the nanocellulose is (1-10):100, and the concentration of the cross-linking agent in the inorganic nanomaterial solution is 0.001 mg / ml-0.25 mg / ml, for example, 0.001 mg / ml, 0.005 mg / ml, 0.01 mg / ml, 0.05 mg / ml, 0.1 mg / ml, 0.15 mg / ml, 0.2 mg / ml, 0.25 mg / ml, etc.

[0090] Exemplarily, when the inorganic nanomaterial solution further includes a crosslinking agent, depositing the inorganic nanomaterial solution to obtain a thin film includes:

[0091] Depositing the inorganic nanomaterial solution to obtain a film layer to be cross-linked;

[0092] The film layer to be cross-linked is heat-treated for 10 minutes to 60 minutes (for example, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, etc.) in an environment with a temperature of 80°C to 100°C (for example, 80°C, 85°C, 90°C, 95°C, 100°C, etc.) and a humidity of 80% to 100% (for example, 80%, 85%, 90%, 95%, 100%, etc.), so that the cross-linking agent and the nanocellulose undergo a cross-linking reaction to obtain a film.

[0093] S120, depositing an inorganic nanomaterial solution to obtain a film, wherein the film includes nanocellulose and inorganic nanoparticles, wherein the nanocellulose forms a porous skeleton, and the inorganic nanoparticles are located in the pores of the porous skeleton.

[0094] It should be noted that the porous skeleton of nanocellulose in the film is formed during the film-forming process.

[0095] For example, the inorganic nano material solution can be deposited by spin coating. It should be noted that when the inorganic nano material solution is deposited by spin coating, part of the solvent in the inorganic nano material solution will be thrown off due to the centrifugal effect during the spin coating process, and the spin coating process is also accompanied by natural volatilization, so the film (thin film) obtained after the spin coating is almost a dry film, and no additional drying treatment is required.

[0096] It is understandable that when other methods (such as inkjet printing) are used to deposit the inorganic nanomaterial solution, the wet film layer formed by the inorganic nanomaterial solution can also be dried (such as heated or naturally evaporated) to obtain a dry film.

[0097] See also Figure 2 and Figure 3 The embodiment of the present application provides a photoelectric device 100, including a first electrode 20 and a second electrode 70 arranged opposite to each other and a thin film 50 arranged between the first electrode 20 and the second electrode 70. The thin film 50 can be a thin film in any of the above embodiments or a thin film prepared by the preparation method in any of the above embodiments.

[0098] See also Figure 2 and Figure 3 The optoelectronic device 100 may further include a substrate 10 , which is disposed on a side of the first electrode 20 facing away from the film 50 .

[0099] Exemplarily, the substrate 10 may be a flexible substrate or a rigid substrate; Exemplarily, the material of the flexible substrate 10 may be an organic polymer, such as polyethylene terephthalate (PET) or polyimide (PI); Exemplarily, the rigid substrate 10 may be a glass substrate.

[0100] It can be understood that when the substrate 10 is a flexible substrate 10 , the optoelectronic device 100 is a flexible optoelectronic device 100 .

[0101] Please combine Figure 2 When the first electrode 20 is an anode and the second electrode 70 is a cathode, the photoelectric device 100 also includes a hole injection layer 30 and a hole transport layer 40 located between the film 50 and the first electrode 20, and an electron transport layer 60 located between the film 50 and the second electrode 70, wherein the hole injection layer 30 is arranged close to the first electrode 20, and the hole transport layer 40 is arranged close to the film 50.

[0102] Please combine Figure 3When the first electrode 20 is a cathode and the second electrode 70 is an anode, the photoelectric device 100 also includes an electron transport layer 60 located between the film 50 and the first electrode 20 and a hole injection layer 30 and a hole transport layer 40 located between the film 50 and the second electrode 70, wherein the hole injection layer 30 is arranged close to the second electrode 70, and the hole transport layer 40 is arranged close to the film 50.

[0103] Exemplarily, the material of the hole transport layer 40 includes 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (Poly-TPD). 、N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tri(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), poly(N-vinylcarbazole) (PVK) and its derivatives, N,N'-bis(1-naphthyl)-N,N '-Diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), poly(phenylene vinylene) (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene] (MOMO-PPV), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-omeTAD), 4,4'-cyclohexylbis[N,N-di(4- At least one of poly(4-(4-methylphenyl)aniline) (TAPC), 1,3-di(carbazole-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, polyspirofluorene and its derivatives, polythiophene (TPH) and its derivatives.

[0104] Exemplarily, the material of the hole injection layer 30 includes poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), copper phthalocyanine (CuPc), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), poly(ethylenedioxythiophene) (PEDOT), PEDOT:PSS doped with MoO 3 Derivatives (PEDOT:PSS-MoO 3 ), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), tetracyanoquinodimethane (F4-TCNQ), at least one of a transition metal oxide and a transition metal sulfide compound. Exemplarily, the transition metal oxide may include MoO x , VO x , WO x CrO x , CuO or more. Exemplarily, the metal sulfide compound may include MoS 2 、MoSe 2 , WS 2 ,WSe 2 , CuS or more.

[0105] Exemplarily, the first electrode 20 and the second electrode 70 can be independently selected from a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode. The material of the doped metal oxide electrode can include, but is not limited to, one or more of indium doped tin oxide (ITO), fluorine doped tin oxide (FTO), antimony doped tin oxide (ATO), aluminum doped zinc oxide (AZO), gallium doped zinc oxide (GZO), indium doped zinc oxide (IZO), magnesium doped zinc oxide (MZO), aluminum doped magnesium oxide (AMO), and cadmium doped zinc oxide. The composite electrode is an electrode formed by stacking two or more layers of conductive materials, such as AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO 2 / Ag / TiO 2 、TiO 2 / Al / TiO 2 , ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF 2 / Al、CsF / Al、CaCO 3 / Al、BaF 2 / Ca / Al, etc., where " / " represents a stacked structure, for example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer and an AZO layer stacked in sequence. The material of the metal single substance electrode may include but is not limited to one or more of silver (Ag), magnesium (Mg), aluminum (Al), gold (Au), gallium (Ga), nickel (Ni), platinum (Pt), iridium (Ir), copper (Cu), molybdenum (Mo), calcium (Ca), and barium (Ba). The alloy electrode includes but is not limited to an Au:Mg alloy electrode or an Ag:Mg alloy electrode.

[0106] In some embodiments, one of the first electrode 20 and the second electrode 70 serving as an anode may be an electrode with a relatively high work function, for example, it may include but is not limited to one or more of a doped metal oxide electrode with a relatively high work function, a metal single substance electrode with a relatively high work function, and a carbon nanotube electrode; the material of the metal single substance electrode with a relatively high work function may be Ni, Pt, Au, Ag or Ir, etc.

[0107] In some embodiments, one of the first electrode 20 and the second electrode 70 that serves as a cathode may be an electrode with a relatively low work function, for example, it may include but is not limited to a metal single substance electrode with a relatively low work function, a composite electrode with a relatively low work function, and an alloy electrode with a relatively low work function; the material of the metal single substance electrode with a relatively low work function may be Ca, Ba, Al, Mg, etc.; the structure of the composite electrode with a relatively low work function may be Ca / Al, LiF / Ca, LiF / Al, BaF 2 / Al、CsF / Al、CaCO 3 / Al、BaF 2 / Ca / Al, etc.; the alloy electrode with relatively low work function can be Au:Mg or Ag:Mg, etc.

[0108] Exemplarily, the thickness of each of the first electrode 20 and the second electrode 70 can be 10nm-120nm, for example, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, 105nm, 110nm, 115nm, 120nm, etc.

[0109] Exemplarily, the thickness of the hole injection layer 30 is 10 nm-50 nm, for example, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, 45 nm, 48 nm, 50 nm, etc.

[0110] Exemplarily, the thickness of the hole transport layer 40 is 10 nm-50 nm, for example, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, 45 nm, 48 nm, 50 nm, etc.

[0111] Exemplarily, the thickness of the electron transport layer 60 is 10 nm-50 nm, for example, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, 45 nm, 48 nm, 50 nm, etc.

[0112] See also Figure 4 , while combining Figure 2 and Figure 3 , the present application embodiment provides a method for preparing a photoelectric device, comprising:

[0113] S210 , providing a photoelectric device preform, wherein the photoelectric device preform includes a first electrode 20 .

[0114] Please combine Figure 2 and Figure 3 The optoelectronic device preform may further include a substrate 10 , and a first electrode 20 is disposed on one side of the substrate 10 .

[0115] S220 , preparing a thin film 50 on the first electrode 20 by using the thin film preparation method in any of the above embodiments.

[0116] S230 , forming a second electrode 70 on the thin film 50 to obtain the optoelectronic device 100 .

[0117] Please combine Figure 2 , when the first electrode 20 is an anode and the second electrode 70 is a cathode, the thin film 50 is prepared on the first electrode 20 by using the thin film preparation method in any of the above embodiments, including: forming a hole injection layer 30 on the first electrode 20, forming a hole transport layer 40 on the hole injection layer 30 on a side away from the first electrode 20, and preparing the thin film 50 on the hole transport layer 40 by using the thin film preparation method in any of the above embodiments;

[0118] The forming of the second electrode 70 on the thin film 50 includes: forming an electron transport layer 60 on the thin film 50 , and forming the second electrode 70 on a side of the electron transport layer 60 away from the thin film 50 .

[0119] Please combine Figure 3, when the first electrode 20 is a cathode and the second electrode 70 is an anode, the method for preparing a thin film in any of the above embodiments is used to prepare a thin film 50 on the first electrode 20, comprising: forming an electron transport layer 60 on the first electrode 20, and forming a thin film 50 on a side of the electron transport layer 60 away from the first electrode 20 using the method for preparing a thin film in any of the above embodiments;

[0120] The forming of the second electrode 70 on the film 50 includes: forming a hole transport layer 40 on the film 50 , forming a hole injection layer 30 on the side of the hole transport layer 40 away from the film 50 , and forming the second electrode 70 on the side of the hole injection layer 30 away from the hole transport layer 40 .

[0121] An embodiment of the present application further provides a display device, comprising the optoelectronic device in any of the above embodiments or an optoelectronic device manufactured by the method for manufacturing the optoelectronic device in any of the above embodiments.

[0122] Exemplarily, the display device can be a mobile terminal such as a television, a mobile phone, a tablet computer, a computer monitor, or a gaming device, an augmented reality (AR) device, a virtual reality (VR) device, a data storage device, an audio playback device, a video playback device, a wearable device, or other device with a display screen, wherein the wearable device can be a smart bracelet, smart glasses, a smart watch, smart decoration, etc.

[0123] The optoelectronic device and the method for preparing the same according to the embodiment of the present application are described in detail below in the form of specific embodiments.

[0124] Film Example 1

[0125] This embodiment provides a thin film, and the preparation method thereof includes:

[0126] Cellulose nanofibers (manufacturer Nanografi, the mass ratio of cellulose nanofibers to quantum dots is 0.03:1) were added to the quantum dot solution (solvent is octane) to prepare a quantum dot-nanocellulose composite solution. In the quantum dot-nanocellulose composite solution, the concentration of quantum dots (CdZnSe) is 30 mg / ml, and the concentration of cellulose nanofibers is 0.9 mg / ml. The quantum dot-nanocellulose composite solution was spin coated on the hole transport layer at a rotation speed of 2000 rpm for 30 seconds to obtain a thin film with a thickness of 30 nm.

[0127] Film Example 2

[0128] The present embodiment provides a film, and its preparation method is different from that of film embodiment 1, in that, when preparing the quantum dot-nanocellulose composite solution, the mass ratio of cellulose nanofibers to quantum dots is different, thereby making the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution different; in this embodiment 2, the mass ratio of cellulose nanofibers to quantum dots in the quantum dot-nanocellulose composite solution is 0.01:1, the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution is 0.3 mg / ml, and the concentration of quantum dots (CdZnSe) is 30 mg / ml.

[0129] Film Example 3

[0130] The present embodiment provides a film, and its preparation method is different from that of film embodiment 1 in that, when preparing the quantum dot-nanocellulose composite solution, the mass ratio of cellulose nanofibers to quantum dots is different, thereby making the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution different; in this embodiment 3, the mass ratio of cellulose nanofibers to quantum dots in the quantum dot-nanocellulose composite solution is 0.05:1, the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution is 0.5 mg / ml, and the concentration of quantum dots (CdZnSe) is 30 mg / ml.

[0131] Film Example 4

[0132] This embodiment provides a film, and its preparation method is different from that of film embodiment 1 in that different types of nanocellulose are used in preparing the quantum dot-nanocellulose composite solution. The nanocellulose used in embodiment 1 is cellulose nanofiber, while the nanocellulose used in embodiment 4 is cellulose nanocrystals (manufacturer Nanografi).

[0133] Film Example 5

[0134] This embodiment provides a film, and its preparation method is different from that of film embodiment 1, in that different types of nanocellulose are used in preparing the quantum dot-nanocellulose composite solution. The nanocellulose used in embodiment 1 is cellulose nanofiber, while the nanocellulose used in embodiment 5 is bacterial nanocellulose (manufacturer Cellulose Lab).

[0135] Film Example 6

[0136] The present embodiment provides a film, and the preparation method thereof is different from that of film embodiment 1 in that a crosslinking agent 3-aminopropyltriethoxysilane (Sigma Aldrich, APTES, cas 919-30-2) is further added to the quantum dot-nanocellulose composite solution, wherein the concentration of 3-aminopropyltriethoxysilane is 0.02 mg / ml, and at this time, the mass ratio between 3-aminopropyltriethoxysilane and cellulose nanofibers is 2.22:100; and after spin coating the quantum dot-nanocellulose composite solution on the hole transport layer, a film layer to be crosslinked is obtained, and the film layer to be crosslinked is placed in a constant temperature and humidity chamber at a temperature of 80° C. and a humidity of 80% for 10 minutes, so that the silane in the film layer to be crosslinked reacts with the nanocellulose to obtain a film.

[0137] Film Example 7

[0138] The present embodiment provides a film, and the preparation method thereof is different from that of film embodiment 1 in that a crosslinking agent maleic anhydride (Sigma Aldrich, cas108-31-6) is further added to the quantum dot-nanocellulose composite solution, wherein the concentration of maleic anhydride is 0.08 mg / ml, and at this time, the mass ratio of maleic anhydride to cellulose nanofibers is 8.89:100; and after spin coating the quantum dot-nanocellulose composite solution on the hole transport layer, a film layer to be crosslinked is obtained, and the film layer to be crosslinked is heat-treated on a hot plate at 100° C. for 30 minutes, so that the silane in the film layer to be crosslinked undergoes a crosslinking reaction with the nanocellulose to obtain a film.

[0139] Film Example 8

[0140] The present embodiment provides a film, and its preparation method is different from that of film embodiment 1 in that, in the quantum dot-nanocellulose composite solution, the mass ratio of cellulose nanofibers to quantum dots is different, thereby making the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution different; in this embodiment 8, the mass ratio of cellulose nanofibers to quantum dots in the quantum dot-nanocellulose composite solution is 0.001:1, and the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution is 0.03 mg / ml.

[0141] Film Example 9

[0142] The present embodiment provides a film, and its preparation method is different from that of film embodiment 1 in that, in the quantum dot-nanocellulose composite solution, the mass ratio of cellulose nanofibers to quantum dots is different, thereby making the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution different; in this embodiment 9, the mass ratio of cellulose nanofibers to quantum dots in the quantum dot-nanocellulose composite solution is 0.1:1, and the concentration of cellulose nanofibers in the quantum dot-nanocellulose composite solution is 3 mg / ml.

[0143] Photoelectric device embodiment 10

[0144] This embodiment provides a photoelectric device, and the preparation method thereof includes:

[0145] Step S1: Spin-coating PEDOT:PSS on a PET / ITO substrate at a rotation speed of 5000 rpm for 30 seconds, followed by heating at 150° C. for 15 minutes to obtain a hole injection layer having a thickness of 25 nm;

[0146] Step S2: Spin-coat TFB on the PEDOT layer in the previous step at a rotation speed of 3000 rpm for 30 seconds, then UV treat for 10 minutes, and then heat at 200°C for 10 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0147] Step S3: forming a thin film on the hole transport layer using the method of thin film embodiment 1;

[0148] Step S4: spin coating a zinc oxide (ZnO) solution (ZnO concentration is 30 mg / mL) on the film at a rotation speed of 3000 rpm for 30 seconds, followed by heating at 80° C. for 30 minutes to obtain an electron transport layer having a thickness of 30 nm;

[0149] Step S6: When the vacuum degree is not higher than 3×10 -4 Pa, Ag was evaporated at a rate of 1 angstrom / second for 1000 seconds to obtain a cathode with a thickness of 100 nm, thereby obtaining a top-emitting upright quantum dot light-emitting device.

[0150] Photoelectric device embodiment 11

[0151] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 2.

[0152] Photoelectric device embodiment 12

[0153] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 3.

[0154] Photoelectric device embodiment 13

[0155] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 4.

[0156] Photoelectric device embodiment 14

[0157] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 5.

[0158] Photoelectric device embodiment 15

[0159] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 6.

[0160] Photoelectric device embodiment 16

[0161] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 7.

[0162] Photoelectric device embodiment 17

[0163] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 8.

[0164] Photoelectric device embodiment 18

[0165] This embodiment provides a photoelectric device, and the difference between its preparation method and that of embodiment 10 is that in step S3, a thin film is formed on the hole transport layer by the method of thin film embodiment 9.

[0166] Photoelectric device comparative example 1

[0167] This embodiment provides a photoelectric device, and its preparation method is different from that of Example 10, except that the method for preparing the thin film in step S3 includes: spin coating a quantum dot solution on a hole transport layer at a rotation speed of 2000 rpm for 30 seconds to obtain a thin film with a thickness of 30 nm. The quantum dot solution consists of quantum dots CdZnSe and a solvent (octane), wherein the concentration of the quantum dots CdZnSe is 30 mg / ml.

[0168] Performance Test:

[0169] The performance tests were conducted on the photoelectric devices prepared in the photoelectric device examples 10-18 and the photoelectric device comparative example 1 to test the initial performance (maximum brightness L max , lifespan T95) and the lifespan loss of optoelectronic devices after different bending times at room temperature (25°C) and high temperature (80°C);

[0170] Among them, the maximum brightness L max The test method is: using FSD FPD optical characteristic measurement equipment, controlling the efficiency test system built by QE PRO spectrometer, Keithley 2400, and Keithley 6485 through LabView, measuring parameters such as voltage, current, brightness, and luminous spectrum, and recording the maximum brightness L max ;

[0171] The test method of life T95 is: 2 In the gas, under constant current driving, the time taken for the device brightness to decay to a certain proportion of the maximum brightness is measured. The time taken for the brightness to decay to 95% of the maximum brightness is defined as T95. This lifetime is the measured lifetime, where the constant current is 2 mA.

[0172] The calculation formula for the life loss of the optoelectronic device is: (1-device life after bending / initial device life)*100.

[0173] The test results are shown in Tables 1, 2 and 3, where Table 1 shows the life attenuation of the optoelectronic device after different bending times at room temperature (25°C), Table 2 shows the life attenuation of the optoelectronic device after different bending times at high temperature (80°C), and Table 3 shows the initial performance of the optoelectronic device (maximum brightness L max , lifespan T95).

[0174] Table 1. Lifespan degradation of optoelectronic devices after bending for different times (25°C)

[0175]

[0176] Table 2. Attenuation of optoelectronic devices after bending for different times (80°C)

[0177]

[0178] Table 3. Initial performance of optoelectronic devices

[0179]

[0180] It can be seen from Table 1 that under normal temperature conditions (25°C), the life loss percentages of the optoelectronic devices of Examples 10-18 after being bent 20,000 times, 50,000 times, and 150,000 times are all less than the life loss percentages of the optoelectronic devices of Comparative Example 1 after being bent 20,000 times, 50,000 times, and 150,000 times; it can be seen from Table 2 that under high temperature conditions (80°C), the life loss percentages of the optoelectronic devices of Examples 10-18 after being bent 20,000 times, 50,000 times, and 150,000 times are all less than the life loss percentages of the optoelectronic devices of Comparative Example 1 after being bent 20,000 times, 50,000 times, and 150,000 times; that is, That is, compared with Comparative Example 1, the optoelectronic devices of Examples 10-18 have better stability and longer service life at both normal temperature (25°C) and high temperature (80°C); it is known that the films in the optoelectronic devices of Examples 10-18 contain nanocellulose, while the film in the optoelectronic device of Comparative Example 1 does not contain nanocellulose, which means that the film containing nanocellulose still has good stability after multiple bending and has good bending resistance, so that the optoelectronic device containing the film has more stable device performance and longer service life.

[0181] It can be seen from Table 1 that, under normal temperature conditions (25°C), the life loss percentages of the optoelectronic devices of Examples 10-18 after being bent 20,000 times, 50,000 times, and 150,000 times are all less than the life loss percentages of the optoelectronic devices of Example 17 after being bent 20,000 times, 50,000 times, and 150,000 times; it can be seen from Table 2 that under high temperature conditions (80°C), the life loss percentages of the optoelectronic devices of Examples 10-18 after being bent 20,000 times, 50,000 times, and 150,000 times are all less than the life loss percentages of the optoelectronic devices of Example 17 after being bent 20,000 times, 50,000 times, and 150,000 times; that is, compared with Example 17, the optoelectronic devices of Examples 10-18 have a longer life loss under normal temperature conditions (25°C). ) and high temperature conditions (80°C) have better stability and longer service life; it is known that the mass ratio of nanocellulose to quantum dots in the film of the optoelectronic devices of Examples 10-18 is between 0.01:1 and 0.05:1, while the mass ratio of nanocellulose to quantum dots in the film of the optoelectronic device of Example 17 is 0.001:1, which means that when the content of nanocellulose in the film is higher than 0.01:1, when the film is bent, the nanocellulose can well maintain the stability of the position of the quantum dot particles, thereby slowing down or eliminating the generation of cracks or breakages in the film during the bending process, thereby improving the stability and service life of the optoelectronic device.

[0182] It can be seen from Table 2 that under high temperature conditions (80°C), the percentage of life loss of the optoelectronic device of Example 10 after being bent 20,000 times, 50,000 times, and 150,000 times is greater than the percentage of life loss of the optoelectronic devices of Examples 15 and 16 after being bent 20,000 times, 50,000 times, and 150,000 times. In other words, compared with Example 10, the optoelectronic devices of Examples 15 and 16 have better stability and longer service life; it is known that the difference between Examples 15 and 16 and Example 10 is that the film also contains a cross-linking agent, which means that when the film contains a cross-linking agent, the film has better bending resistance, thereby making the optoelectronic device have better stability and a longer service life.

[0183] By observing Table 1, Table 2, and Table 3, it can be seen that although the life loss of the optoelectronic device of Example 18 after bending is low at both room temperature (25°C) and high temperature (80°C), its initial performance is poor, and the maximum brightness L max and lifespan T95 are both low. This is because the content of nanocellulose (cellulose nanofibers) in the film of the optoelectronic device of Example 18 is relatively high, and the mass ratio of nanocellulose to quantum dots is 0.1:1, which is much higher than the mass ratio of nanocellulose to quantum dots in Examples 10-16 (0.01:1 to 0.05:1). This indicates that when the mass ratio of nanocellulose to quantum dots in the film does not exceed 0.05:1, not only the bending resistance of the film can be improved, but also the optoelectronic device can have better luminescence performance and a longer service life.

[0184] The above is a detailed introduction to the thin film and its preparation method, optoelectronic device and its preparation method, and display device provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the present application. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A film, It is characterized in that The invention comprises nanocellulose and inorganic nanoparticles. The nanocellulose has a porous skeleton, and the inorganic nanoparticles are located in the pores of the porous skeleton.

2. The film according to claim 1, It is characterized in that The mass ratio of the nanocellulose to the inorganic nanoparticles is (0.01-0.05):1; and / or The nanocellulose includes at least one of cellulose nanocrystals, cellulose nanofibers and bacterial nanocellulose.

3. The film according to claim 1, It is characterized in that The film further comprises a cross-linking agent, wherein the cross-linking agent comprises at least one of a silane and an anhydride; The silane is attached to the nanocellulose; and / or The anhydride is connected to the nanocellulose; and / or The mass ratio of the cross-linking agent to the nanocellulose is (0.5-10):

100.

4. The film according to claim 3, It is characterized in that The silane is connected to the nanocellulose via at least one silicon-oxygen bond; and / or The acid anhydride is connected to the nanocellulose via at least one ester bond.

5. The film according to claim 3, It is characterized in that The silane comprises at least one of 3-aminopropyltriethoxysilane, methyltrioxysilane, styrenedimethoxysilane and aminopropyltrimethoxysilane; and / or The acid anhydride comprises at least one of maleic anhydride, succinic anhydride and phthalic anhydride; and / or The cross-linking agent is silane, and the mass ratio of the cross-linking agent to the nanocellulose is (0.5-5):100; or The cross-linking agent is an acid anhydride, and the mass ratio of the cross-linking agent to the nanocellulose is (1-10):100; or The crosslinking agent comprises a mixture of silane and anhydride, and the mass ratio of silane to anhydride is (1-100):(1-100).

6. The film according to claim 1, It is characterized in that The material of the inorganic nanoparticles includes at least one of an organic luminescent material and a quantum dot luminescent material, wherein the organic luminescent material includes 4,4'-bis(N-carbazole)-1,1'-biphenyl:tri[2-(p-tolyl)pyridine iridium(III), 4,4',4"-tri(carbazole-9-yl)triphenylamine:tri[2-(p-tolyl)pyridine iridium, diarylanthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, 1,4,7,10-tetra-tert-butylperylene, rubrene derivatives, thermally activated delayed fluorescence materials, exciplex luminescent materials. The quantum dot luminescent material comprises at least one of a single structure quantum dot and a core-shell structure quantum dot, the material of the single structure quantum dot, the core material of the core-shell structure quantum dot and the shell material of the core-shell structure quantum dot each independently comprise at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound, and the shell layer of the core-shell structure quantum dot comprises one or more layers;The II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, Hg At least one of CdZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, wherein the IV-VI group compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, S at least one of nPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, the III-V group compound is selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, and the I-III-VI group compound is selected from at least one of CuInS; 2 、CuInSe 2 AgInS 2 At least one of .

7. A method for preparing a thin film, It is characterized in that include: Providing an inorganic nanomaterial solution, wherein the inorganic nanomaterial solution comprises nanocellulose, inorganic nanoparticles and a solvent; The inorganic nano material solution is deposited to obtain a film, which includes nano cellulose and inorganic nano particles. The nano cellulose forms a porous skeleton, and the inorganic nano particles are located in the pores of the porous skeleton.

8. The method for preparing the thin film according to claim 7, It is characterized in that In the inorganic nanomaterial solution, the concentration of the inorganic nanoparticles is 10 mg / ml to 50 mg / ml, and the concentration of the nanocellulose is 0.1 mg / ml to 2.5 mg / ml; and / or The mass ratio of the nanocellulose to the inorganic nanoparticles is (0.01-0.05):

1.

9. The method for preparing the thin film according to claim 7, It is characterized in that The inorganic nanomaterial solution further comprises a crosslinking agent, wherein the crosslinking agent comprises at least one of silane and anhydride, and the mass ratio of the crosslinking agent to the nanocellulose is (0.5-10):100; The concentration of the cross-linking agent in the inorganic nano material solution is 0.0005 mg / ml to 0.25 mg / ml.

10. The method for preparing a thin film according to claim 9, It is characterized in that When the cross-linking agent is silane, the mass ratio of the cross-linking agent to the nanocellulose is (0.5-5):100, and the concentration of the cross-linking agent in the inorganic nanomaterial solution is 0.0005 mg / ml-0.125 mg / ml; When the cross-linking agent is an acid anhydride, the mass ratio of the cross-linking agent to the nanocellulose is (1-10):100, and the concentration of the cross-linking agent in the inorganic nanomaterial solution is 0.001 mg / ml-0.25 mg / ml.

11. The method for preparing a thin film according to claim 9, It is characterized in that Depositing the inorganic nano material solution to obtain a thin film comprises: Depositing the inorganic nanomaterial solution to obtain a film layer to be cross-linked; The film layer to be cross-linked is heat-treated for 10 minutes to 60 minutes in an environment with a temperature of 80° C. to 100° C. and a humidity of 80% to 100% so that the cross-linking agent reacts with the nanocellulose to obtain a film.

12. A photoelectric device, It is characterized in that include: a first electrode; a second electrode, arranged opposite to the first electrode; A film is arranged between the first electrode and the second electrode, and the film is a film as described in any one of claims 1 to 6 or a film prepared by the method for preparing a film as described in any one of claims 7 to 11.

13. The optoelectronic device according to claim 12, It is characterized in that When the first electrode is an anode and the second electrode is a cathode, the photoelectric device further comprises a hole injection layer and a hole transport layer between the film and the first electrode, and an electron transport layer between the film and the second electrode, wherein the hole injection layer is disposed close to the first electrode, and the hole transport layer is disposed close to the film; or When the first electrode is a cathode and the second electrode is an anode, the photoelectric device further comprises an electron transport layer between the film and the first electrode, and a hole injection layer and a hole transport layer between the film and the second electrode, wherein the hole injection layer is arranged close to the second electrode, and the hole transport layer is arranged close to the film.

14. The optoelectronic device according to claim 13, It is characterized in that The materials of the hole transport layer include 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N, N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'- diphenyl-1,1'-biphenyl-4-4'-diamine, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], 1 , 3-di(carbazole-9-yl)benzene, polyaniline, polypyrrole, poly(p-)phenylene vinylene, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, polyspirofluorene and its derivatives, polythiophene and its derivatives; and / or The material of the hole injection layer includes at least one of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and its derivatives, copper phthalocyanine, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, poly(dioxyethylthiophene), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, transition metal oxides and transition metal sulfur compounds; and / or The material of the electron transport layer includes at least one of metal oxide, doped metal oxide, II-VI semiconductor material, III-V semiconductor material and I-III-VI semiconductor material, and the metal oxide is selected from ZnO, BaO, TiO 2 SnO 2 At least one of the following; the metal oxide in the doped metal oxide is selected from ZnO, TiO 2 SnO 2 At least one of the doping elements is selected from at least one of Al, Mg, Li, In, and Ga; the II-VI semiconductor material is selected from at least one of ZnS, ZnSe, and CdS; the III-V semiconductor material is selected from at least one of InP and GaP; the I-III-VI semiconductor material is selected from at least one of CuInS and CuGaS; and / or The first electrode and the second electrode are independently selected from a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode. The material of the doped metal oxide particle electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide. The composite electrode includes AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO 2 / Ag / TiO 2 、TiO 2 / Al / TiO 2 , ZnS / Ag / ZnS or ZnS / Al / ZnS, the material of the metal single substance electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba.

15. A method for preparing a photoelectric device, It is characterized in that include: Providing a photoelectric device preform, wherein the photoelectric device preform comprises a first electrode; Prepare a thin film on the first electrode using the thin film preparation method according to any one of claims 7 to 11; A second electrode is formed on the film to obtain a photoelectric device.

16. The method for preparing a photoelectric device according to claim 15, It is characterized in that When the first electrode is an anode and the second electrode is a cathode, the method for preparing a thin film on the first electrode using the method for preparing a thin film as described in any one of claims 7 to 11 comprises: forming a hole injection layer on the first electrode, forming a hole transport layer on the side of the hole injection layer away from the first electrode, and preparing a thin film on the hole transport layer using the method for preparing a thin film as described in any one of claims 7 to 11; and / or The forming of the second electrode on the thin film comprises: forming an electron transport layer on the thin film, and forming the second electrode on a side of the electron transport layer away from the thin film.

17. The method for preparing a photoelectric device according to claim 15, It is characterized in that When the first electrode is a cathode and the second electrode is an anode, the method for preparing a thin film on the first electrode using the method for preparing a thin film as described in any one of claims 7 to 11 comprises: forming an electron transport layer on the first electrode, and forming a thin film on a side of the electron transport layer away from the first electrode using the method for preparing a thin film as described in any one of claims 7 to 11; and / or The forming of the second electrode on the film comprises: forming a hole transport layer on the film, forming a hole injection layer on the side of the hole transport layer away from the film, and forming the second electrode on the side of the hole injection layer away from the hole transport layer.

18. A display device, It is characterized in that The invention comprises a photoelectric device as claimed in any one of claims 12 to 14 or a photoelectric device prepared by the method for preparing a photoelectric device as claimed in any one of claims 15 to 17.

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